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-rw-r--r--common/image-fit.c584
1 files changed, 584 insertions, 0 deletions
diff --git a/common/image-fit.c b/common/image-fit.c
new file mode 100644
index 0000000000..4f5c1f16c8
--- /dev/null
+++ b/common/image-fit.c
@@ -0,0 +1,584 @@
+/*
+ * Copyright (C) Jan Lübbe, 2014
+ *
+ * This code is inspired by the U-Boot FIT image code.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) "FIT: " fmt
+#include <common.h>
+#include <init.h>
+#include <boot.h>
+#include <libfile.h>
+#include <fdt.h>
+#include <digest.h>
+#include <of.h>
+#include <fs.h>
+#include <malloc.h>
+#include <linux/ctype.h>
+#include <asm/byteorder.h>
+#include <errno.h>
+#include <linux/err.h>
+#include <stringlist.h>
+#include <rsa.h>
+#include <image-fit.h>
+
+#define FDT_MAX_DEPTH 32
+#define FDT_MAX_PATH_LEN 200
+
+#define CHECK_LEVEL_NONE 0
+#define CHECK_LEVEL_HASH 1
+#define CHECK_LEVEL_SIG 2
+#define CHECK_LEVEL_MAX 3
+
+static uint32_t dt_struct_advance(struct fdt_header *f, uint32_t dt, int size)
+{
+ dt += size;
+ dt = ALIGN(dt, 4);
+
+ if (dt > f->off_dt_struct + f->size_dt_struct)
+ return 0;
+
+ return dt;
+}
+
+static char *dt_string(struct fdt_header *f, char *strstart, uint32_t ofs)
+{
+ if (ofs > f->size_dt_strings)
+ return NULL;
+ else
+ return strstart + ofs;
+}
+
+static int of_read_string_list(struct device_node *np, const char *name, struct string_list *sl)
+{
+ struct property *prop;
+ const char *s;
+
+ of_property_for_each_string(np, name, prop, s) {
+ string_list_add(sl, s);
+ }
+
+ return prop ? 0 : -EINVAL;
+}
+
+static int fit_digest(void *fit, struct digest *digest,
+ struct string_list *inc_nodes, struct string_list *exc_props,
+ uint32_t hashed_strings_start, uint32_t hashed_strings_size)
+{
+ struct fdt_header *fdt = fit;
+ uint32_t dt_struct;
+ void *dt_strings;
+ struct fdt_header f = {};
+ int stack[FDT_MAX_DEPTH];
+ char path[FDT_MAX_PATH_LEN];
+ char *end;
+ uint32_t tag;
+ int start = -1;
+ int depth = -1;
+ int want = 0;
+
+ f.totalsize = fdt32_to_cpu(fdt->totalsize);
+ f.off_dt_struct = fdt32_to_cpu(fdt->off_dt_struct);
+ f.size_dt_struct = fdt32_to_cpu(fdt->size_dt_struct);
+ f.off_dt_strings = fdt32_to_cpu(fdt->off_dt_strings);
+ f.size_dt_strings = fdt32_to_cpu(fdt->size_dt_strings);
+
+ if (hashed_strings_start > f.size_dt_strings ||
+ hashed_strings_size > f.size_dt_strings ||
+ hashed_strings_start + hashed_strings_size > f.size_dt_strings) {
+ pr_err("%s: hashed-strings too large\n", __func__);
+ return -EINVAL;
+ }
+
+ dt_struct = f.off_dt_struct;
+ dt_strings = (void *)fdt + f.off_dt_strings;
+
+ end = path;
+ *end = '\0';
+
+ do {
+ const struct fdt_property *fdt_prop;
+ const struct fdt_node_header *fnh;
+ const char *name;
+ int include = 0;
+ int stop_at = 0;
+ int offset = dt_struct;
+ int maxlen, len;
+
+ tag = be32_to_cpu(*(uint32_t *)(fit + dt_struct));
+
+ switch (tag) {
+ case FDT_BEGIN_NODE:
+ fnh = fit + dt_struct;
+ name = fnh->name;
+ maxlen = (unsigned long)fdt + f.off_dt_struct +
+ f.size_dt_struct - (unsigned long)name;
+
+ len = strnlen(name, maxlen + 1);
+ if (len > maxlen)
+ return -ESPIPE;
+
+ dt_struct = dt_struct_advance(&f, dt_struct,
+ sizeof(struct fdt_node_header) + len + 1);
+
+ depth++;
+ if (depth == FDT_MAX_DEPTH)
+ return -ESPIPE;
+ if (end - path + 2 + len >= FDT_MAX_PATH_LEN)
+ return -ESPIPE;
+ if (end != path + 1)
+ *end++ = '/';
+ strcpy(end, name);
+ end += len;
+ stack[depth] = want;
+ if (want == 1)
+ stop_at = offset;
+ if (string_list_contains(inc_nodes, path))
+ want = 2;
+ else if (want)
+ want--;
+ else
+ stop_at = offset;
+ include = want;
+
+ break;
+
+ case FDT_END_NODE:
+ dt_struct = dt_struct_advance(&f, dt_struct, FDT_TAGSIZE);
+
+ include = want;
+ want = stack[depth--];
+ while (end > path && *--end != '/')
+ ;
+ *end = '\0';
+
+ break;
+
+ case FDT_PROP:
+ fdt_prop = fit + dt_struct;
+ len = fdt32_to_cpu(fdt_prop->len);
+
+ name = dt_string(&f, dt_strings, fdt32_to_cpu(fdt_prop->nameoff));
+ if (!name)
+ return -ESPIPE;
+
+ dt_struct = dt_struct_advance(&f, dt_struct,
+ sizeof(struct fdt_property) + len);
+
+ include = want >= 2;
+ stop_at = offset;
+ if (string_list_contains(exc_props, name))
+ include = 0;
+
+ break;
+
+ case FDT_NOP:
+ dt_struct = dt_struct_advance(&f, dt_struct, FDT_TAGSIZE);
+
+ include = want >= 2;
+ stop_at = offset;
+
+ break;
+
+ case FDT_END:
+ dt_struct = dt_struct_advance(&f, dt_struct, FDT_TAGSIZE);
+
+ include = 1;
+
+ break;
+
+ default:
+ pr_err("%s: Unknown tag 0x%08X\n", __func__, tag);
+ return -EINVAL;
+ }
+
+ if (!dt_struct)
+ return -ESPIPE;
+
+ pr_debug("%s: include %d, want %d, offset 0x%x, len 0x%x\n",
+ path, include, want, offset, dt_struct-offset);
+
+ if (include && start == -1)
+ start = offset;
+
+ if (!include && start != -1) {
+ pr_debug("region: 0x%p+0x%x\n", fit + start, offset - start);
+ digest_update(digest, fit + start, offset - start);
+ start = -1;
+ }
+ } while (tag != FDT_END);
+
+ pr_debug("region: 0x%p+0x%x\n", fit + start, dt_struct - start);
+ digest_update(digest, fit + start, dt_struct - start);
+
+ pr_debug("strings: 0x%p+0x%x\n", dt_strings+hashed_strings_start, hashed_strings_size);
+ digest_update(digest, dt_strings + hashed_strings_start, hashed_strings_size);
+
+ return 0;
+}
+
+/*
+ * The consistency of the FTD structure was already checked by of_unflatten_dtb()
+ */
+static int fit_verify_signature(struct device_node *sig_node, void *fit)
+{
+ uint32_t hashed_strings_start, hashed_strings_size;
+ struct string_list inc_nodes, exc_props;
+ struct rsa_public_key key = {};
+ struct digest *digest;
+ int sig_len;
+ const char *algo_name, *key_name, *sig_value;
+ char *key_path;
+ struct device_node *key_node;
+ enum hash_algo algo;
+ void *hash;
+ int ret;
+
+ if (of_property_read_string(sig_node, "algo", &algo_name)) {
+ pr_err("algo not found\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (strcmp(algo_name, "sha1,rsa2048") == 0) {
+ algo = HASH_ALGO_SHA1;
+ } else if (strcmp(algo_name, "sha256,rsa4096") == 0) {
+ algo = HASH_ALGO_SHA256;
+ } else {
+ pr_err("unknown algo %s\n", algo_name);
+ ret = -EINVAL;
+ goto out;
+ }
+ digest = digest_alloc_by_algo(algo);
+ if (!digest) {
+ pr_err("unsupported algo %s\n", algo_name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ sig_value = of_get_property(sig_node, "value", &sig_len);
+ if (!sig_value) {
+ pr_err("signature value not found in %s\n", sig_node->full_name);
+ ret = -EINVAL;
+ goto out_free_digest;
+ }
+
+ if (of_property_read_string(sig_node, "key-name-hint", &key_name)) {
+ pr_err("key name not found in %s\n", sig_node->full_name);
+ ret = -EINVAL;
+ goto out_free_digest;
+ }
+ key_path = xasprintf("/signature/key-%s", key_name);
+ key_node = of_find_node_by_path(key_path);
+ free(key_path);
+ if (!key_node) {
+ pr_info("failed to find key node\n");
+ ret = -ENOENT;
+ goto out_free_digest;
+ }
+
+ ret = rsa_of_read_key(key_node, &key);
+ if (ret) {
+ pr_info("failed to read key in %s\n", key_node->full_name);
+ ret = -ENOENT;
+ goto out_free_digest;
+ }
+
+ if (of_property_read_u32_index(sig_node, "hashed-strings", 0, &hashed_strings_start)) {
+ pr_err("hashed-strings start not found in %s\n", sig_node->full_name);
+ ret = -EINVAL;
+ goto out_free_digest;
+ }
+ if (of_property_read_u32_index(sig_node, "hashed-strings", 1, &hashed_strings_size)) {
+ pr_err("hashed-strings size not found in %s\n", sig_node->full_name);
+ ret = -EINVAL;
+ goto out_free_digest;
+ }
+
+ string_list_init(&inc_nodes);
+ string_list_init(&exc_props);
+
+ if (of_read_string_list(sig_node, "hashed-nodes", &inc_nodes)) {
+ pr_err("hashed-nodes property not found in %s\n", sig_node->full_name);
+ ret = -EINVAL;
+ goto out_sl;
+ }
+
+ string_list_add(&exc_props, "data");
+
+ digest_init(digest);
+ ret = fit_digest(fit, digest, &inc_nodes, &exc_props, hashed_strings_start, hashed_strings_size);
+ hash = xzalloc(digest_length(digest));
+ digest_final(digest, hash);
+
+ ret = rsa_verify(&key, sig_value, sig_len, hash, algo);
+ if (ret) {
+ pr_info("image signature BAD\n");
+ ret = -EBADMSG;
+ } else {
+ pr_info("image signature OK\n");
+ ret = 0;
+ }
+
+ free(hash);
+ out_sl:
+ string_list_free(&inc_nodes);
+ string_list_free(&exc_props);
+ out_free_digest:
+ digest_free(digest);
+ out:
+ return ret;
+}
+
+static int fit_verify_hash(struct device_node *hash, const void *data, int data_len)
+{
+ struct digest *d;
+ const char *algo;
+ const char *value_read;
+ char *value_calc;
+ int hash_len, ret;
+
+ value_read = of_get_property(hash, "value", &hash_len);
+ if (!value_read) {
+ pr_err("%s: \"value\" property not found\n", hash->full_name);
+ return -EINVAL;
+ }
+
+ if (of_property_read_string(hash, "algo", &algo)) {
+ pr_err("%s: \"algo\" property not found\n", hash->full_name);
+ return -EINVAL;
+ }
+
+ d = digest_alloc(algo);
+ if (!d) {
+ pr_err("%s: unsupported algo %s\n", hash->full_name, algo);
+ return -EINVAL;
+ }
+
+ if (hash_len != digest_length(d)) {
+ pr_err("%s: invalid hash length %d\n", hash->full_name, hash_len);
+ ret = -EINVAL;
+ goto err_digest_free;
+ }
+
+ value_calc = xmalloc(hash_len);
+
+ digest_init(d);
+ digest_update(d, data, data_len);
+ digest_final(d, value_calc);
+
+ if (memcmp(value_read, value_calc, hash_len)) {
+ pr_info("%s: hash BAD\n", hash->full_name);
+ ret = -EBADMSG;
+ } else {
+ pr_info("%s: hash OK\n", hash->full_name);
+ ret = 0;
+ }
+
+ free(value_calc);
+
+err_digest_free:
+ digest_free(d);
+
+ return ret;
+}
+
+static int fit_open_image(struct fit_handle *handle, const char *unit, const void **outdata,
+ unsigned long *outsize)
+{
+ struct device_node *image = NULL, *hash;
+ const char *type = NULL, *desc= "(no description)";
+ const void *data;
+ int data_len;
+ int ret = 0;
+
+ image = of_get_child_by_name(handle->root, "images");
+ if (!image)
+ return -ENOENT;
+
+ image = of_get_child_by_name(image, unit);
+ if (!image)
+ return -ENOENT;
+
+ of_property_read_string(image, "description", &desc);
+ pr_info("image '%s': '%s'\n", unit, desc);
+
+ of_property_read_string(image, "type", &type);
+ if (!type) {
+ pr_err("No \"type\" property found in %s\n", image->full_name);
+ return -EINVAL;
+ }
+
+ data = of_get_property(image, "data", &data_len);
+ if (!data) {
+ pr_err("data not found\n");
+ return -EINVAL;
+ }
+
+ if (handle->verify > BOOTM_VERIFY_NONE) {
+ ret = -EINVAL;
+ for_each_child_of_node(image, hash) {
+ if (handle->verbose)
+ of_print_nodes(hash, 0);
+ ret = fit_verify_hash(hash, data, data_len);
+ if (ret < 0)
+ return ret;
+ }
+ }
+ if (ret < 0)
+ return ret;
+
+ *outdata = data;
+ *outsize = data_len;
+
+ return 0;
+}
+
+static int fit_open_configuration(struct fit_handle *handle, const char *name)
+{
+ struct device_node *conf_node = NULL, *sig_node;
+ const char *unit, *desc = "(no description)";
+ int ret;
+
+ conf_node = of_get_child_by_name(handle->root, "configurations");
+ if (!conf_node)
+ return -ENOENT;
+
+ if (name) {
+ unit = name;
+ } else if (of_property_read_string(conf_node, "default", &unit)) {
+ unit = "conf@1";
+ }
+
+ conf_node = of_get_child_by_name(conf_node, unit);
+ if (!conf_node) {
+ pr_err("configuration '%s' not found\n", unit);
+ return -ENOENT;
+ }
+
+ of_property_read_string(conf_node, "description", &desc);
+ pr_info("configuration '%s': %s\n", unit, desc);
+
+ if (IS_ENABLED(CONFIG_FITIMAGE_SIGNATURE) &&
+ handle->verify == BOOTM_VERIFY_SIGNATURE) {
+ ret = -EINVAL;
+ for_each_child_of_node(conf_node, sig_node) {
+ if (handle->verbose)
+ of_print_nodes(sig_node, 0);
+ ret = fit_verify_signature(sig_node, handle->fit);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (ret < 0)
+ return ret;
+ }
+
+ if (of_property_read_string(conf_node, "kernel", &unit) == 0) {
+ ret = fit_open_image(handle, unit, &handle->kernel, &handle->kernel_size);
+ if (ret)
+ return ret;
+ } else {
+ return -ENOENT;
+ }
+
+ if (of_property_read_string(conf_node, "fdt", &unit) == 0) {
+ ret = fit_open_image(handle, unit, &handle->oftree, &handle->oftree_size);
+ if (ret)
+ return ret;
+ }
+
+ if (of_property_read_string(conf_node, "ramdisk", &unit) == 0) {
+ ret = fit_open_image(handle, unit, &handle->initrd, &handle->initrd_size);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+struct fit_handle *fit_open(const char *filename, const char *config, bool verbose,
+ enum bootm_verify verify)
+{
+ struct fit_handle *handle = NULL;
+ const char *desc = "(no description)";
+ int ret;
+
+ handle = xzalloc(sizeof(struct fit_handle));
+
+ handle->verbose = verbose;
+
+ ret = read_file_2(filename, &handle->size, &handle->fit, FILESIZE_MAX);
+ if (ret) {
+ pr_err("unable to read %s: %s\n", filename, strerror(-ret));
+ goto err;
+ }
+
+ handle->root = of_unflatten_dtb(handle->fit);
+ if (IS_ERR(handle->root)) {
+ ret = PTR_ERR(handle->root);
+ goto err;
+ }
+
+ handle->verify = verify;
+
+ of_property_read_string(handle->root, "description", &desc);
+ pr_info("'%s': %s\n", filename, desc);
+
+ ret = fit_open_configuration(handle, config);
+ if (ret)
+ goto err;
+
+ return handle;
+ err:
+ if (handle->root)
+ of_delete_node(handle->root);
+ free(handle->fit);
+ free(handle);
+
+ return ERR_PTR(ret);
+}
+
+void fit_close(struct fit_handle *handle)
+{
+ if (handle->root)
+ of_delete_node(handle->root);
+ if (handle->fit)
+ free(handle->fit);
+ free(handle);
+}
+
+#ifdef CONFIG_SANDBOX
+static int do_bootm_sandbox_fit(struct image_data *data)
+{
+ struct fit_handle *handle;
+ handle = fit_open(data->os_file, data->os_part, data->verbose);
+ if (handle)
+ fit_close(handle);
+ return 0;
+}
+
+static struct image_handler sandbox_fit_handler = {
+ .name = "FIT image",
+ .bootm = do_bootm_sandbox_fit,
+ .filetype = filetype_oftree,
+};
+
+static int sandbox_fit_register(void)
+{
+ return register_image_handler(&sandbox_fit_handler);
+}
+late_initcall(sandbox_fit_register);
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-20 08:27:07 +0000